1. Field of the Invention
The present invention pertains to a surgical instrument for removing a fistula, and in particular, to a surgical instrument including a thin bar that is inserted into a fistulous tract and a cutting tool cooperating with the bar for coring the fistulous tract from the surrounding tissue.
2. Brief Description of the Art
The conventional technique for removing a peri-anal fistula, for example, requires making a deep incision from the edge of the anus in the plane of the fistula until the incision reaches the fistula. The fistula is then excised from the surrounding tissue and removed from the patient.
However, such an incision cuts the lower fibers of the anal sphincter that traverse the course of the incision. Therefore, this operation is likely to impair the patients stool or flatus continence, especially if the fistula is located a relatively large distance from the anus or is recurrent. Such an operation also leaves a large cavity which usually takes many weeks to heal. During the long healing period, the patient suffers pain, requires frequent dressings, and is likely to be absent from work. This can result in a significant economic loss for the patient. Furthermore, in a high peri-anal fistula, where the fistula is located a relatively large distance from the anus, the above-described operation can not be used because incontinence would be inevitable from the relatively large incision that would be required.
Removing a high peri-anal fistula requires diverting the faeces to a defunctioning colostomy, then surgically removing the fistula using the procedure discussed above. A few months later the colostomy is closed. It can be easily appreciated that this treatment for a high perianal fistula entails a great deal of suffering and risk for the patient and has a high cost.